In modern computer systems, including in particular enterprise-level systems, redundant storage is often used to protect against data loss (e.g., in the case of drive failure). Many data redundancy strategies and systems are known in the art, such as data mirroring, data striping, and the like. Many such systems utilize a group of hard disks to provide redundancy in case a single disk fails.
The configuration of a typical redundant storage system often is defined by several configurable options (such as, for example, the type of data mirroring, the number of partners assigned to each disk, the amount of bandwidth dedicated to rebalance operations, etc.), and cost and/or relative effectiveness of the system in ensuring data availability, performance, etc. is generally heavily dependent on the options selected.
While reliability statistics about individual hard disks are available (often from the manufacturers of such disks), reliability statistics about redundant storage systems are generally unpublished (at least in part because they are heavily dependent on the configuration of the particular system of interest and/or the disks incorporated in the system). Moreover, because such systems, by design, are relatively reliable, it is difficult to experimentally determine their failure rates.
Hence, it is often difficult to evaluate the relative effectiveness of various data redundancy strategies and/or to select an optimal configuration for a data storage system,